Google Pay API for React Native on Android

1. Introduction

What you'll build

At the completion of this codelab, you will have a minimum viable React Native app with a working Google Pay integration for Android. This project retrieves a payment token which may be sent to a payment service provider for processing.

What you'll learn

  • How to install and configure the Google Pay React Native library
  • How to display the Google Pay button and handle clicks
  • How to request a payment token from Google Pay

What you'll need

  • A text editor of your choice to edit JavaScript files.
  • A React Native development environment set up for Android.
  • For production, you will need a Google Pay merchantId. It only takes a minute to register at Google Pay & Wallet Console so might as well take care of it now.

2. Create the React Native project

Create project files

  1. Create a new React Native project named googlepayrn.
    npx @react-native-community/cli@latest init googlepayrn
  2. Install the Google Pay React Native library.
    cd googlepayrn
npm install @google/react-native-make-payment
  3. Open App.tsx in your IDE of choice and replace the contents with the following code:
    import React from 'react';
import {
  SafeAreaView,
  StatusBar,
  StyleSheet,
  Text,
  useColorScheme,
  View,
} from 'react-native';

const App = () => {
  const isDarkMode = useColorScheme() === 'dark';

  const backgroundStyle = {
    backgroundColor: isDarkMode ? '#121212' : '#F3F3F3',
  };

  return (
    <SafeAreaView style={backgroundStyle}>
      <StatusBar
        barStyle={isDarkMode ? 'light-content' : 'dark-content'}
        backgroundColor={backgroundStyle.backgroundColor}
      />
      <View style={styles.container}>
        <Text style={styles.title}>Google Pay Codelab</Text>
        <View id="gpay-container" />
        <Text>Transaction info and errors will be logged to the console.</Text>
      </View>
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  container: {
    padding: 24,
  },
  title: {
    fontSize: 24,
    fontWeight: '600',
    marginBottom: 24,
  },
});

export default App;

3. Configure Google Pay

A Google Pay payment request requires a request object. The object defined here as baseGooglePayRequest contains the minimum common settings for all requests. Additional settings will be added depending on the request made which we'll review in this codelab.

Add the Google Pay configuration constants to App.tsx:

// This is the base configuration for all Google Pay payment data requests.
const baseGooglePayRequest = {
  apiVersion: 2,
  apiVersionMinor: 0,
  allowedPaymentMethods: [
    {
      type: 'CARD',
      parameters: {
        allowedAuthMethods: [
          "PAN_ONLY", "CRYPTOGRAM_3DS"
        ],
        allowedCardNetworks: [
          "AMEX", "DISCOVER", "INTERAC", "JCB", "MASTERCARD", "VISA"
        ]
      },
      tokenizationSpecification: {
        type: 'PAYMENT_GATEWAY',
        parameters: {
          gateway: 'example',
          gatewayMerchantId: 'exampleGatewayMerchantId'
        }
      }
    }
  ]
};

Resources

  • API Reference: Google Pay API request objects documentation
  • API Reference: Refer to PaymentMethod for more information about the allowed authorization methods, allowed card networks, and tokenization specifications including the proper gateway value.

4. Make a payment request

When the Google Pay button is pressed, a payment request is created and shown.

Add the payment details and payment methods to App.tsx:

const paymentDetails = {
  total: {
    amount: {
      currency: 'USD',
      value: '14.95',
    },
  },
};

const paymentMethods = [
  {
    supportedMethods: 'google_pay',
    data: baseGooglePayRequest,
  },
];

5. Add the Google Pay button

The react-native-make-payment library includes a native Google Pay button component.

  1. Add the import at the top of App.tsx:
import { GooglePayButton, GooglePayButtonConstants, PaymentRequest } from '@google/react-native-make-payment';
  1. Add the click handler inside the App component:
const checkCanMakePayment = () => {
  const paymentRequest = new PaymentRequest(paymentMethods, paymentDetails);
  paymentRequest.canMakePayment().then((canMakePayment) => {
    if (canMakePayment) {
      paymentRequest.show().then((response) => {
        console.log(response);
      });
    } else {
      console.log('Google Pay unavailable');
    }
  });
};
  1. Add the button and style to the JSX and its style:
<GooglePayButton
  style={styles.googlepaybutton}
  onPress={checkCanMakePayment}
  allowedPaymentMethods={baseGooglePayRequest.allowedPaymentMethods}
  theme={GooglePayButtonConstants.Themes.Dark}
  type={GooglePayButtonConstants.Types.Buy}
  radius={4}
/>

googlepaybutton: {
  width: 200,
  height: 48,
},

App.tsx after adding the button and handler:

import React from 'react';
import {
  SafeAreaView,
  StatusBar,
  StyleSheet,
  Text,
  useColorScheme,
  View,
} from 'react-native';
import { GooglePayButton, GooglePayButtonConstants, PaymentRequest } from '@google/react-native-make-payment';

const baseGooglePayRequest = {
  apiVersion: 2,
  apiVersionMinor: 0,
  allowedPaymentMethods: [
    {
      type: 'CARD',
      parameters: {
        allowedAuthMethods: [
          'PAN_ONLY', 'CRYPTOGRAM_3DS'
        ],
        allowedCardNetworks: [
          'AMEX', 'DISCOVER', 'INTERAC', 'JCB', 'MASTERCARD', 'VISA'
        ]
      },
      tokenizationSpecification: {
        type: 'PAYMENT_GATEWAY',
        parameters: {
          gateway: 'example',
          gatewayMerchantId: 'exampleGatewayMerchantId'
        }
      }
    }
  ]
};

const paymentDetails = {
  total: {
    amount: {
      currency: 'USD',
      value: '14.95',
    },
  },
};

const paymentMethods = [
  {
    supportedMethods: 'google_pay',
    data: baseGooglePayRequest,
  },
];

const App = () => {
  const isDarkMode = useColorScheme() === 'dark';

  const backgroundStyle = {
    backgroundColor: isDarkMode ? '#121212' : '#F3F3F3',
  };

  const checkCanMakePayment = () => {
    const paymentRequest = new PaymentRequest(paymentMethods, paymentDetails);
    paymentRequest.canMakePayment().then((canMakePayment) => {
      if (canMakePayment) {
        paymentRequest.show().then((response) => {
          // Send 'token' to your payment service provider (PSP)
          console.log(response);
        });
      } else {
        console.log('Google Pay unavailable');
      }
    });
  };

  return (
    <SafeAreaView style={backgroundStyle}>
      <StatusBar
        barStyle={isDarkMode ? 'light-content' : 'dark-content'}
        backgroundColor={backgroundStyle.backgroundColor}
      />
      <View style={styles.container}>
        <Text style={styles.title}>Google Pay Codelab</Text>
        <GooglePayButton
          style={styles.googlepaybutton}
          onPress={checkCanMakePayment}
          allowedPaymentMethods={baseGooglePayRequest.allowedPaymentMethods}
          theme={GooglePayButtonConstants.Themes.Dark}
          type={GooglePayButtonConstants.Types.Buy}
          radius={4}
        />
        <Text>Transaction info and errors will be logged to the console.</Text>
      </View>
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  container: {
    padding: 24,
  },
  title: {
    fontSize: 24,
    fontWeight: '600',
    marginBottom: 24,
  },
  googlepaybutton: {
    width: 200,
    height: 48,
  },
});

export default App;

Code explanation

  1. paymentDetails describes the transaction that should be processed.
  2. paymentMethods configures supported methods; for Google Pay use google_pay with baseGooglePayRequest.
  3. checkCanMakePayment shows the payment sheet when available and logs the response.

6. Conclusion

Congratulations on completing this Codelab! You have learned how to integrate the Google Pay API into a React Native app for Android.

Run the project

Run the following command to start your app:

npx react-native run-android

Where to go from here

Additional resources